Traditional digital networks have been characterized as synchronous or store and forward. Synchronous networks are used primarily for carrying voice signals which must be delivered at the destination in a synchronous manner and without undue delay. Variation in the delivery rate of samples will result in distortion of the recreated voice signal and extended end to end delays in the delivery are unacceptable from a human factors point of view. Store and forward or packet networks have been used primarily for transporting business data (files, credit queries, etc.) none of Which are impacted by end to end delays normally encountered in these networks. Packet networks are more efficient in the utilization of network band width since they can take advantage of statistical utilization and loading factors. For example, a synchronous network carrying a voice conversation must allocate resources even when there is no meaningful signal present. TASI (Time Assigned Speech Interpolation) has increased utilization of these facilities, however, utilization has not approached the efficiency of a pure packet network.
With the availability of high speed digital networks (100 megabits/sec and above), it is possible to employ packet networks to carry synchronous signals such as digitized voice without experiencing the difficulties set forth above. However, as the number of independent networks (and bridges interconnecting them) increases, the end to end delay increases. This increase is a direct result of the processing time required to pass from one network to another through a bridge interconnecting them. A primary object of the invention disclosed herein is to reduce the processing time required to transfer a packet from one network to another thus decreasing the end to end delay in transmissions extending over a large number of networks interconnected by bridges. In so doing extending the distance or domain over which synchronous traffic can flow in packet form.